Thanks for getting back to this thread, @Ralphthefluffycat.

Let share with you some insights on why your sales tax payable' account shows a negative amount. 

The reason behind this is that your clients categorize your downloaded tax payments in a liability account type. Doing this will show a negative balance on it since they are no bills created to offset these payments. It's like creating a bill payment checks without having a bill. 

To correct this, you have to create a journal entry to zero out the balance in the Sales Tax Payable account. Let me show you how:

1. Click the +New icon and select Journal entry. 
2. Select the Sales Tax Payable account in the first line and enter the amount on the CREDITS column. 
3. Choose the offsetting account in the second line and enter the amount in the DEBITS column.
4. Click Save.

You can also reach out to your accountant for further advice on what account you'll need to use in the second line.

In addition, you can run the Quick Report of your accounts in QuickBooks. This way, you can check transactions that affecting its balance. Just go to the Accounting menu and select Chart of Accounts. Look for the account and click the drop-down arrow beside the View register, then choose Run report.

Please let me know if there's anything else I can do to be of assistance. I'll be more than happy to help. Have a wonderful day, and stay safe.